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How To: Solve for the missing ratios or proportions

In this video the tutor shows how to solve the missing ratios or proportions. He explains it with an example, where a number in one of the ratios is missing and he intends to find this value. He shows the example of cross multiplication, where you multiply the values on the either side of the equation diagonally and finally solves the equation which results in the value of the unknown value. This is an introductory video explaining how to use rations and proportions to find missing values.

How To: Find a slope of a straight line with: Ax + By + C = 0

In this video the instructor shows how to find the slope of an equation which is in the form Ax + By + C = 0. He says that the formula to find the slope of a line in the above form is slope m = -A/B, where A and B are the numeric constants of the variables x and y in the given equation. He goes on and further shows how to do this with a couple of examples. He shows how to reduce any equation into the general form and how to apply the slope formula then. This video shows how to find the slope ...

How To: Calculate percent error in chemistry lab activities

If you want to know how to calculate percent error easily, you should watch this video. Error is the amount of deviation from accurate values. Error calculation is not possible, unless you make a quantitative measurement of the various quantities involved in your experiment. Measurement can help us in calculating errors and knowing how right we are in our theoretical models. In calculating percent error, We need to get the experimental value and the value which you are aiming at, which is the...

How To: Convert numbers in and out of standard form

In this video, we learn how to convert numbers in and out of standard form. Standard form is a useful way of writing down very large numbers and very small numbers. To do this, you will look at the number you have and ignore the zeros that are just at the end. Then, write down the basic numbers. Put a decimal point in this number to make it between one and ten. Now, write down x 10 and put the power for how many places the decimal point moved to get to the new number. This will help you write...

How To: Calculate the age of the universe w/ Hubble's constant

This is a great instructional video on how to calculate the age of Universe from Hubble's constant. The speed the galaxy moves away from us is directly proportional to the distance from us. Now think of big bang theory. Hubble's constant is equal to velocity over distance. 1 over Hubble's constant is equal to distance over velocity that is equal to time. Time equals to 1over 71. If you change it into all the same units words it is one over 71000 or 3.09x 10 to the power of 22. It is 3.09x10 t...

How To: Find percent by mass & percent composition

In chemistry you come across problems which ask you to find the percent by mass and percent composition of each element in a chemical compound. To do this the first step is to compute the molar mass. Use the periodic table to look up the mass of individual atoms and multiply it by the number of atoms to find the mass of that element. Now add up all the masses to arrive at the molar mass of the compound. Now to find the percent composition of an element divide the total mass of each element by...

How To: Calculate the area of a parallelogram

Calculating The Area Of A Parallelogram A parallelogram is a 4-sided shape formed by two pairs of parallel lines. Opposite sides are equal in length and opposite angles are equal in measure. To find the area of a parallelogram, multiply the base by the height. The formula is:

How To: Cancel out in basic algebra

This video gives you brief tutorial on simplifying expressions, or canceling out common factors. He starts out by answering the question "What is canceling?" and demonstrates a basic example. You find the greatest common factor between the numerator and denominator, which you then divide both by. This can also be done if you have variables in your fraction. He then shows it can be done the same way if you have binomials in your fractions. However, you must be careful that the denominator does...

How To: Translate a sentence into math symbols

We will be translating the sentence "twice y differs from 5 by more than two, “into a mathematical equation. The word twice generally means two times, so 2*y (because y comes next in the sentence). Differs normally means is different and a difference from something in a mathematical sentence means subtraction most of the time, thus minus five. We don't know if we’re talking about below 5 or above 5 on the number line, so we put absolute value around the equation. More than implies a greater t...

How To: Use ">" (greater than) and "<" (less than) symbols

In this video the author explains how to identify the less than (<) and greater than (>) symbols and when to use them. She explains to us to relate the numbers to animals stating that the smaller numbers are smaller animals and bigger numbers are bigger animals. Now she tells us to imagine that smaller animals are eaten up by the larger animals. So she shows a smaller number comes on the left side of '<' sign and bigger number comes on the right side of '<' sign stating that the bigger number...

How To: Evaluate a line integral along a straight line segment

This video tutorial is in the Education category which will show you how to evaluate a line integral along a straight line segment using the definition of the line integral. This video evaluates a line integral along a straight line segment using a parametric representation of the curve (using a vector representation of the line segment) and then integrating. A vector representation of a line that starts at r0 and ends at r1 is r(t) = (1-t)r0 + tr1 where t is greater than equal to 0 and lesse...

How To: Understand fractions with patterns

This is an educational site where we can learn about math lessons with example videos, interactive practice problems and can do self-test. The associate teacher in the video teaches us about fraction problems. She has written four numbers on the board, which is 1 1/4, 1 1/2, 1 3/4, and 2. She explains how to find the next three numbers following the same pattern. The teacher in the video tells that the key in solving the problem is to think of 1 1/2 as 1 2/4. Each number in the given problem ...

How To: Use the distance formula for two points

In this tutorial, we learn how to use the distance formula for two points. The distance formula is D= the square root of (X2-X1) squared, plus (Y2 minus Y1) squared. It may look confusing, but it's just a derivation of a theorem. First, find the two points that you have and graph them. If you want to know the distance between them, you cannot just count squares if it's a diagonal line. If you remember geometry, you can draw a right triangle over the line to figure out the distance. After this...

How To: Find the area of irregular shapes

This video explains how to find the area of irregular shapes. Draw the shape on a grid or graph paper. This will help you divide your shape into pieces. Draw dotted lines to divide the shape into squares, rectangles or triangles. For instance, if you have an "L" shape, you can divide the shape into two rectangles. Be sure your shapes do not overlap. Calculate the area of each individual shape. The graph paper will help you determine the length and width of each shape. Add the resulting areas ...

How To: Remember "greater than" & "less than" symbols

This video shows you how to easily remember "greater than" and "less than" math symbols. The first thing you have to remember is that "less than" symbol looks like the letter L ("less than" symbol is "<"). When you see this sign, remember that < looks like L and means "less than". The other symbol, "greater than" does not look like the letter L, therefore it cannot be "less than" and it's easier to remember. The "greater than" symbol is ">". That's it! Good Luck!

How To: Find a number given Its percent

This how-to video is about how to find a number when its percent is given. This video is really helpful and effective in finding the number when the percent is given, the following steps are explained in the video to find the number when its percent is given:

How To: Subtract fractions with unlike denominators

In order to subtract mixed fractions, you'll need to look at the denominators carefully. If the denominators do not match, you'll need to find a common denominator. For example, 5 2/3 minus 3 4/5 do not have the same denominator. The lowest common denominator for them is 15.

How To: Calculate the volume of a triangular solid or triangular prism

With mathematics, as with anything else, not everyone progresses at the same rate. Geometry is no exception. Happily, in the age of Internet video tutorials, this isn't a problem. Those who progress quickly can go beyond what's being taught them and those who are struggling likewise have all the time in the world to catch up. With this free video math lesson, you'll learn how to calculate the volume of a triangular prism.

How To: Calculate the height and volume of a pyramid

Need to know how to calculate the height and volume of a pyramid in geometry? Learn how with this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test).

How To: Use a formula to calculate the volume of a cube

Calculating the volume of a cube is very important in high school geometry classes. Calculating the volume of a solid can be confusing at first, but with a little practice you will be able to get it right. In this tutorial, high school math teacher Doug Simms teaches you exactly how to calculate the volume of a cube and offers examples so you can follow along. Listen to Mr. Simms and you will be at the top of your class!

How To: Calculate weight if given the mass

The video shows how to calculate weight if the mass is given and vice versa.Later on in this unit you will learn about Newton's laws of motion and Newton's second law of motion gives us a way to change mass into weight and vice versa.This law will tell you what is happening to objects when the net force on the object is not equal to zero and the easy way to say what will happen is that the object will accelerate.But how much the object accelerates depends on two things,firstly the mass of the...

How To: Find the formula of a piecewise function given a graph

This video shows how to find the formula of a piecewise function when given a graph. The first step is to write a definition for the graph, which is done by identifying the different domains shown in the graph. The second step is writing formulas for each domain specified by the lines in the graph. The point-slope formula is used to identify the slope and y-intercept for the leftmost domain, which has a sloped line. A point and horizontal line make for simpler equations in the other pieces of...

How To: Calculate percentages in your head

This video explains how to calculate percentages in your head. To calculate a percentage in your head, start by breaking the percentage off into smaller units. For example 25% is 10 + 10 + 5. 30% is 10, 10, and 10. Now you have numbers you can easily work with in your head. Find 10% of the number. This is easily done by one of two methods. You can either move the decimal point one place to the left or you can drop the last number. Dropping the last number sometimes gives you an estimate, thou...

How To: Find a percentage of a whole number in basic math

Need help figuring out how to find a given percentage of a whole number (e.g., 16% of 736)? Watch this free video lesson. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this free math tutorial, you'll learn how to find percentage values in basic arit...

How To: Factor trinomials using the Berry factoring method

In this free video math lesson YAY MATH, we learn how to factor trionmials using the Berry method. With mathematics, as with anything else, not everyone progresses at the same rate. Algebra is no exception. Happily, in the age of Internet video tutorials, this isn't a problem. Those who progress quickly can go beyond what's being taught them and those who are struggling likewise have all the time in the world to catch up. Whether you need help finishing your homework or studying for that next...

How To: Estimate probabilities with the empirical rule

Learn how to use the empirical rule (or 68-95-99.7 rule) to estimate probabilities for normal distributions in statistics. From Ramanujan to calculus co-creator Gottfried Leibniz, many of the world's best and brightest mathematical minds have belonged to autodidacts. And, thanks to the Internet, it's easier than ever to follow in their footsteps (or just finish your homework or study for that next big test). With this installment from Internet pedagogical superstar Salman Khan's series of fre...

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